by Panos Charitos. Published: 24 March 2015

During the last Collaboration Board, the ALICE Thesis Award Committee presented Deepa Thomas with the ALICE Thesis Award for her thesis "Jet like heavy-flavour particle correlations in proton-proton and lead-lead collisions in ALICE" under the supervision of Prof. Andre Mischke. We met Deepa and asked her about her research project and future plans. 

1) What was the topic of your thesis?

The title of my thesis is "Jet-like heavy-flavour particle correlations in proton-proton and lead-lead collisions in ALICE" where I looked at the azimuthal angular correlations between electrons coming from the decay of heavy-flavour hadrons (D and B hadrons) and charged particles.

The question that was addressed in the thesis was to study the properties of heavy-flavour jets in lead-lead collisions. We wanted to understand if the fragmentation and hadronization of heavy quarks are modified by the medium effects. The azimuthal angular correlations of high pT particles are an alternative probe to study back-to-back jet events. In pp collisions we also wanted to measure the contribution of D and B mesons to the heavy-flavour decay electron sample.



 2) Which are the main results obtained and the outcome of your work?

In pp collisions, the near-side (DeltaPhi ~ 0)  correlation distribution was fitted with MC templates to obtain the relative fraction of electrons from beauty decays. The measurement showed that the heavy-flavour decay electrons mainly come from the decays of D mesons at low pT, but as we go to higher pT (pT > 5 GeV/c) contributions from beauty decays start to dominate. This is consistent with various perturbative QCD calculations.

In Pb-Pb collisions, the yield on the near side correlation distribution was obtained and compared with the one obtained from pp collisions. With the limited statistics available from Run1, the results show that there is no difference in the yield in pp and Pb-Pb data. We are looking forward to the Run2 data to be able to make more precise measurements.

3) What is your previous background and how did you move into physics?

I obtained my masters degree in physics from University of Mysore, India. I was highly inspired by my Professors to do research in physics especially in the field of particle physics. For my Masters project I worked in the 'India based Neutrino observatory' where I was part of building and testing prototypes of 'resistive plate chamber' detectors. In 2009, I moved to Utrecht University to pursue PhD studies in the ALICE experiment.


4) Finally a few words about your future plans: what you did after your PhD and your medium to long-term plans? 

I am currently working as a postdoctoral fellow at the University of Texas at Austin. On a long term basis, I am planning to continue doing research in the field of high energy/heavy-ion physics.